Hi @hisgeneral, thank you for participating in the Industrial Electrical Homework. We have assessed your Homework post , and the below captures our assessments.

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A. You have correctly identified two transformers in the figure. The working of a transformer can be understood by looking at the voltage supply.

I have done my homework to find out the transformer's turn ratio. You have figured out the voltage ratio. I hope you understand your mistake.

B. You have correctly presented the working and description of various parts of a power transformer. You will learn about tripping relays in the next lesson as you get to know the different parts of a transformer.

C. A three-phase transformer is used to load your home electrical load. The answer to your question is that these transformers are rated as 200 KVA. Due to the low rating and low output load, oil heating is low, so the Buchloj relay and temperature meter are not used. For higher ratings, such as MVA, transformers have safety devices. I hope your question is answered.

D. You will need at least 6000 KVA or 6 MVA transformers for a 5000 KW load because you cannot use equal-load transformers. I hope you understand.

E. You have made a mistake in some parts when making the specifications for the transformer given in the picture. For example, Energy Pack is a transformer company name. Then you mentioned 415kV, which would be 415 volts low voltage side. I hope you understand.

F. There is an interesting point in this section. You may notice that the HT and LT currents in the above picture of the 2.5 MVA transformer are similar. That means your calculation is correct. It was a very interesting account that intelligent students would understand.

G. If the power factor is low, the electricity is wasted. Basically, power factor improvement is done by using capacitors or synchronous motors to reduce the wastage of electricity. Your guess is correct.

H. You could not give the main differences between the two transformers. For example, it would be great to show the difference between the input and output voltages.

The efficiency of the transformer is higher than other electrical devices because there are no rotating parts in it. This is what you did wrong. I hope you understand.

Thank you very much for completing the Industrial Electrical Lesson homework. Hopefully, you have learned about transformers, which are very important electrical topics in the industrial sector. I have corrected your wrong points. I wish you success.